Exponential , Sine , Cosine Integrals for the HP-41

This program is supplied without representation or warranty of any kind.
Jean-Marc Baillard and The Museum of HP Calculators therefore assume no
responsibility and shall have no liability, consequential or otherwise, of
any kind arising from the use of this program material or any part thereof.

-This program will not work if x is too small:
-Divergence already appears too soon for x = 29 but if you add
RND X<>Y RND X<>Y after line 48
and run the program in FIX 6 ( for instance ) you will have
a good approximation:

-The program below uses this complex continued fraction to compute
Ci(x) & Si(x) for x greater or equal to 3 ( use the program at the top for smaller x-values )
-The number of loops is fixed to 22 ( line 03 ) to produce accurate
results for x >= 3

-In fact, the series expansions still produce 9 exact decimals for x
= 6
-So, if you want to use the continued fraction for x > 6 only, the
number of required loops may be decreased:
-Simply replace line 03 by 14 and the execution time is reduced to
23 seconds.